The present invention relates to a method of automatically calibrating a microprocessor controlled digital multimeter and more specifically to a method where the system includes self-calibration and diagnostic features.
In the calibration of existing multimeters zero and full scale manual adjustments are made periodically (one week to three month intervals) by use of control knobs and a meter indicating a null condition. This routine is time consuming and complex and does not ensure long term stability. In addition if a parameter or component is seriously outside of tolerable limits the user has no simple diagnostic tool for troubleshooting.